JPH05157144A - Epicycle reduction gear - Google Patents

Abstract

PURPOSE:To reliably prevent the occurrence of seizure and wear and to reduce the occurrence of the backlash of the gearing part of each constituting part. CONSTITUTION:The solar gears 48, 54, and 60 of gear reduction mechanisms 47, 53, and 59 are axially positioned in a way that ball bearings 41-44 are arranged between a bottom cover 45, solar gears 48, 54, and 60 at respective stages, and a carrier 64 at a final stage. Rolling grooves 48A, 54C, 60C, and 64C are formed in the respective track surfaces on the one side, over which balls 41A-44A are slid, of the ball bearings 41-44, and the track surfaces on the other side thereof form flat track surfaces 45B, 48B, 54D, and 60D to perform radial positioning.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planetary gear speed reducer having a plurality of speed reduction stages, and more particularly to a planetary gear speed reducer suitably used for a crawler belt drive such as a hydraulic excavator or a hydraulic crane.

[0002]

2. Description of the Related Art FIGS. 5 and 6 show, as an example of a planetary gear speed reducer according to the prior art, a crawler belt drive device such as a hydraulic excavator having a three-stage speed reducer.

In the figure, reference numeral 1 denotes a cylindrical support member fixed to a machine frame of a vehicle body, a hydraulic motor 2 as a rotation source is built in one end side of the support member 1, and the other end side thereof. A tooth portion 1A that meshes with a hub 13 described later is formed, and
A stopper portion 1B for axially positioning a carrier 33 described later is formed.

Reference numeral 3 denotes a cylindrical housing with a lid which serves as a rotating body. The housing 3 includes a drum 4 located on the outer peripheral side of the support member 1 and a ring gear 5 provided with an internal gear 5A on the inner peripheral side. The ring gear 5 and the bottom cover 6 cover the ring gear 5. The drum 4 is rotatably supported by the support member 1 via bearings 7, a crawler belt driving sprocket 8 is attached to the outer peripheral side of the drum 4 via bolts 9, and the ring gear 5 is attached via bolts 10. Is fixed to the drum 4 and the bottom cover 6 is fixed to the ring gear 5 via bolts 11.

A cylindrical projection 6A is provided on the inner side of the bottom cover 6 so as to be located at the center of the shaft, and the projection 6A is provided with a bottomed recess 6B which opens to one side. .. A liner 12 that is in sliding contact with the tip end surface of a sun gear 17 described later is fitted in the recess 6B. Further, the bearing 7 is provided on the outer peripheral side of the stopper portion 1B of the support member 1 by the hub 13
And, it is axially positioned by the nut 14.
Here, the hub 13 has tooth portions 13A and 13B formed on the inner and outer circumferences, the inner tooth portion 13A is meshed with the tooth portion 1A of the support member 1, and the outer tooth portion 13B is the tooth portion 33A of the carrier 33.
The carrier 33 is fixed to the support member 1 with rotation restricted by engaging with the support member 1.

Reference numeral 15 denotes a rotary shaft for deriving a rotary output of the hydraulic motor 2. One end of the rotary shaft 15 is connected to the hydraulic motor 2 and the other end thereof extends toward the bottom cover 6 and will be described later. The first stage sun gear 17 is formed, and the tip end surface is in sliding contact with the liner 12.

Reference numeral 16 denotes a first stage reduction gear mechanism. The reduction gear mechanism 16 has a sun gear 17 formed integrally with the rotation shaft 15 on the tip side of the rotation shaft 15, the sun gear 17 and a ring gear. 5 is arranged so as to mesh with the internal gear 5A,
A planetary gear 1 that revolves around the sun gear 17 while revolving around it.
8, a pin 20 for rotatably supporting the planetary gear 18 via a bearing 19, and the pin 20 fixed to the planetary gear 1
It is composed of a carrier 21 that transmits the revolution of No. 8 to the next-stage sun gear 23 described later. The sun gear 17 may be formed as a separate member from the rotating shaft 15 and attached thereto.

On the other hand, reference numeral 22 denotes a second reduction gear mechanism which is an intermediate reduction gear, and the reduction gear mechanism 22 is the rotary shaft 1
5, the sun gear 23 in which the small diameter tooth portion 23A meshes with the tooth portion 21A of the first stage carrier 21 and only the revolution of the carrier 21 is transmitted, and the large diameter tooth portion 23 of the sun gear 23.
B and an internal gear 5A of the ring gear 5, and a planetary gear 24 that revolves around the sun gear 23 while revolving around the sun gear 23; and a pin 26 that rotatably supports the planetary gear 24 via a bearing 25. The pin 26 is fixed to the carrier 27 for transmitting the revolution of the planetary gear 24 to the final stage sun gear 29 described later.

Reference numeral 28 denotes a third reduction gear mechanism which is the final reduction gear. The reduction gear mechanism 28 is the rotary shaft 1
5, the sun gear 29 in which the small diameter tooth portion 29A meshes with the tooth portion 27A of the second stage carrier 27 and only the revolution of the carrier 27 is transmitted, and the large diameter tooth portion 29 of the sun gear 29.
B and an internal gear 5A of the ring gear 5, and a planetary gear 30 that revolves around the sun gear 29 while revolving around the sun gear 29, and a pin 32 that rotatably supports the planetary gear 30 via a bearing 31. The pin 32 is fixed, and a tooth portion 33A that meshes with the inner tooth portion 13A of the hub 13 on the inner circumference of the one end side.
And a carrier 33 that is positioned in the rotational direction by meshing the outer tooth portion 13B of the hub 13 with the tooth portion 1A of the support member 1.
One end surface 33B of the sun gear 2 is in contact with the stopper portion 1B of the support member 1 to be positioned in one axial direction, and the sun gear 2
9 is in sliding contact with the stopper portion 33C of the carrier 33 and is positioned in the axial direction.

Further, 34 is a spacer for axially positioning the carrier 21 of the first stage, the inner diameter side of the spacer 34 is sandwiched between the sun gears 17 and 23, and the outer diameter side is the cutting of the carrier 21. The spacer 34 is engaged with the recessed step portion 21B to prevent the spacer 34 from falling off and to position the carrier 21 in the axial direction. Reference numeral 35 denotes another spacer for axially positioning the second-stage carrier 27.
The inner diameter side of 5 is sandwiched between the sun gears 24 and 30, and the outer diameter side is engaged with the notch step 27B of the carrier 27 to prevent the spacer 35 from falling off and to position the carrier 27 in the axial direction. There is.

In the planetary gear speed reducer thus constructed, when the rotary shaft 15 is rotated by the hydraulic motor 2, the rotation of the rotary shaft 15 comprises a sun gear 17, a planetary gear 18, a carrier 21 and the like, which is a first stage reduction gear mechanism. The speed is reduced by 16 with a predetermined reduction ratio, and only the revolution of the planetary gear 18 is output from the carrier 21 to the second stage sun gear 23. The second reduction gear mechanism 22 including the sun gear 23, the planetary gear 24, the carrier 27, etc. further reduces the rotation from the carrier 21 at a predetermined reduction ratio, and the planetary gear 24
Output only from the carrier 27 to the final stage sun gear 29. Further, the sun gear 29, the planetary gear 30,
In the final stage reduction gear mechanism 28 including the carrier 33 and the like, since the carrier 33 is positioned in the support member 1 in the rotational direction via the tooth portion 33A, the hub 13 and the tooth portion 1A of the support member 1, The rotation output from the carrier 33 is reduced at a predetermined reduction ratio and transmitted from the sun gear 29 to the ring gear 5 via the planetary gear 30, and a large rotation torque is applied to the housing 3 including the ring gear 5 and the drum 4. Generate.

Thus, the rotational output of the hydraulic motor 2 is sequentially decelerated by the respective reduction gear mechanisms 16, 22, 28, becomes a large torque, is transmitted to the housing 3, and is crawled on the sprocket 8 (not shown). The hydraulic excavator or the like is driven by driving the. Further, an oil liquid serving as lubricating oil is contained in the housing 3 to lubricate the reduction gear mechanisms 16, 22, 28 and the like.

[0013]

By the way, in the above-mentioned prior art, when the gears forming the reduction gear mechanism 16, 22, 28 of each stage rotate, even if the gears are spur gears, Due to the deviation of the machining accuracy, the axial component force is always generated together with the rotating force. As a result, a pair of gears meshing with each other causes a phenomenon in which the gears try to move in the axial direction.

Therefore, in the above-mentioned prior art, the positioning of the first stage sun gear 17 on the other side in the axial direction is performed by sliding contact with the liner 12 fitted to the bottom cover 6. The positioning of the third stage sun gear 29 on one side in the axial direction is performed by using the stopper portion 33C of the carrier 33 and the stopper portion 1B of the support member 1.
Abutting against. Also, the sun gears 17, 2
Positioning between the three is performed by a spacer 34.
Further, the positioning between the sun gears 23 and 29 is performed by the spacer 3
It is done by 5. The overall axial dimension of each sun gear 17, 23, 29 is maintained at an appropriate clearance of about 1 mm, while preventing rattling in the axial direction of each gear.

On the other hand, the carrier 21 in the first stage is the spacer 3
4 and the notch step portion 21B are positioned on the other side in the axial direction, and the tooth portion 21A is in contact with the step portion between the small diameter tooth portion 23A and the large diameter tooth portion 23B of the sun gear 23. Positioning is performed on the one side in the axial direction. Furthermore, 2
Also for the carrier 27 of the step, as in the above, the spacer 3
5 and the notch step portion 27B are positioned to the other side in the axial direction, and the tooth portion 27A contacts the step portion between the small diameter tooth portion 29A and the large diameter tooth portion 29B of the sun gear 29. Positioning is performed on the one side in the axial direction. Therefore, the planetary gears 18, 24, 30 are also axially positioned via the carriers 21, 27.

As described above, in the conventional planetary gear speed reducer, the sun gear 18, the spacers 34, 35, the stopper 33C of the carrier 33, and the sun gear 18,
Axial movement with 24 and 30 is prevented. However, when the planetary gear speed reducer according to this conventional technology is rotationally driven,
It is said that the sun gears 18, 24, 30 rotate in sliding contact with the liner 12 and the spacers 34, 35 that prevent the gears from moving in the axial direction, so that reduction in efficiency of the reduction gear output due to sliding resistance cannot be avoided. There's a problem.

Further, for example, in traveling on a slope, if the bottom cover 6 is driven in a state of being inclined upward, the reduction gear mechanism 1
6,22,28 weigh the liner 12, spacers 34,3
5 and the stopper 33C of the carrier 33,
There is a problem that sliding under a large load causes seizure and wear.

The present invention has been made in view of the above-mentioned problems of the prior art. The present invention aims to improve the efficiency of reduction gear output,
An object of the present invention is to provide a planetary gear speed reducer capable of preventing seizure and wear of each sliding portion.

[0019]

The features of the structure adopted by the present invention to solve the above-mentioned problems are that the sun gear of the first stage and the bottom lid of the housing are between the sun gear of each stage, and Providing a plurality of rolling bearings for axially positioning between the final stage sun gear and the final stage carrier,
A radial positioning means for positioning each rolling bearing in the radial direction is provided.

In this case, the radial positioning means is
It is desirable that the rolling bearing is formed by a concave portion formed on the raceway surface of each rolling bearing and rotatably holding each rolling bearing.

Further, the radial positioning means is formed by an annular projection portion which is formed at a plurality of required positions of the bottom lid of the housing, the sun gears and the carriers, and which positions the rolling bearings in the radial direction. You may.

[0022]

With the above structure, the sun gears can be relatively rotated via the rolling bearings, and the sliding resistance between the sun gears can be greatly reduced. And since each rolling bearing is also positioned radially between each sun gear,
The efficiency of the reduction gear output can be improved without impairing the equal distribution mechanism of each reduction gear mechanism.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS. In the embodiments, the same components as those of the above-described conventional technique are designated by the same reference numerals, and the description thereof will be omitted.

First, a first embodiment of the present invention is shown in FIGS.

In the figure, reference numerals 41, 42, 43 and 44 denote the first, second, third and fourth ball bearings as rolling bearings according to this embodiment, and the ball bearings 41 to 44 are shown in FIG. As shown in FIG. 4, balls 41A to 44A as rolling elements formed of a plurality of steel balls, and the balls 41A to 44A, respectively.
An annular inner cage 4 for holding A to 44A inside and outside
1B to 44B and outer cages 41C to 44C. The first ball bearing 41 is the bottom cover 4 described later.
The second ball bearing 42 is provided between the fifth and first stage sun gears 48.
Between the first stage sun gear 48 and the second stage sun gear 54, the third ball bearing 43 between the second stage sun gear 54 and the last stage sun gear 60, and the fourth stage. The ball bearings 44 are disposed between the final stage sun gear 60 and the final stage carrier 64, respectively.

Reference numeral 45 denotes a bottom cover according to the present embodiment which constitutes a part of the housing 3. The bottom cover 45 is formed in substantially the same manner as the cover body 6 described in the prior art, and is fixed to the ring gear 5 by the bolt 11. However, an annular convex portion 45 located on the axial center side and protruding toward one side is provided inside the bottom lid 45.
A is formed. The tip end surface of the annular convex portion 45A is a flat raceway surface 45B on which the balls 41A of the first ball bearing 41 roll.

Reference numeral 46 denotes a rotary shaft according to this embodiment for deriving the rotary output of the hydraulic motor 2. One end side of the rotary shaft 46 is connected to the hydraulic motor 2 and the other end side extends toward the bottom cover 45. The sun gear 48 of the first stage is formed.

Reference numeral 47 denotes a first-stage reduction gear mechanism. The reduction gear mechanism 47 is disposed on the tip end side of the rotary shaft 45 in the same manner as the first-stage reduction gear mechanism 16 according to the prior art.
A sun gear 48 integrally formed with the sun gear 48, and a planetary gear 49 that is disposed so as to mesh with the sun gear 48 and the internal gear 5A of the ring gear 5 and revolves around the sun gear 48 while rotating around. It is composed of a pin 51 that rotatably supports the planetary gear 49 via a bearing 50, and a carrier 52 to which the pin 51 is fixed and which transmits the revolution of the planetary gear 49 to the next-stage sun gear 54 described later. There is.

Here, the balls 41A of the first ball bearing 41 are provided on the other end surface of the first stage sun gear 48 according to this embodiment.
Rolling groove 48A as a recess at the position of the raceway on which
Is formed annularly so as to form a concentric circle with the sun gear 48,
One end surface is a flat raceway surface 48B on which each ball 42A of the second ball bearing 42 rolls. Then, each ball 41A of the first ball bearing 41 rolls between the raceway surface 45B of the bottom cover 45 and the rolling groove 48A of the sun gear 48, and is radially positioned by the rolling groove 48A, It is designed to prevent falling off.

Reference numeral 53 designates a second reduction gear mechanism which is an intermediate reduction gear. The reduction gear mechanism 53 is loosely fitted on the rotary shaft 45 in substantially the same manner as the second reduction gear mechanism 22 of the prior art. The small-diameter tooth portion 5 is attached to the tooth portion 52A of the first-stage carrier 52.
4A meshes with the sun gear 54 to which only the revolution of the carrier 52 is transmitted, the large-diameter tooth portion 54B of the sun gear 54 and the internal gear 5A of the ring gear 5, and rotates around the sun gear 54. And a planetary gear 55 that revolves while revolving
A pin 57 that rotatably supports 5 through a bearing 56;
The pin 57 is fixed and is constituted by a carrier 58 that transmits the revolution of the planetary gear 55 to a sun gear 60 described later.

Here, each ball 42A of the second ball bearing 42 is provided on the other end surface of the second stage sun gear 54 according to this embodiment.
Rolling groove 54C as a recess at the position of the raceway on which
Is formed annularly so as to form a concentric circle with the sun gear 54,
One side surface is a flat raceway surface 54D on which each ball 43A of the third ball bearing 43 rolls. Each ball 42A of the second ball bearing 42 rolls between the raceway surface 48B of the first stage sun gear 48 and the rolling groove 54C of the second stage sun gear 54, and the rolling groove 54C. Is positioned in the radial direction to prevent the falling off.

Reference numeral 59 denotes a third reduction gear mechanism which is the final reduction gear. The reduction gear mechanism 59 is loosely fitted to the rotary shaft 45 like the third reduction gear mechanism 28 of the prior art. The small-diameter tooth portion 6 is provided on the tooth portion 58A of the second-stage carrier 58.
0A meshes with the sun gear 60 to which only the revolution of the carrier 58 is transmitted, the large gear tooth portion 60B of the sun gear 60 and the internal gear 5A of the ring gear 5 so as to mesh with each other.
0 and a planetary gear 61 arranged around the
A pin 63 that rotatably supports the hub 1 via a bearing 62, the pin 63 is fixed, and the hub 1
3 is formed with a tooth portion 64A that meshes with the inner tooth portion 13A of the hub 3, and the outer tooth portion 13B of the hub 13 is meshed with the tooth portion 1A of the support member 1 so that the carrier 64 is positioned in the rotational direction. Has been done.

Here, each of the balls 43A of the third ball bearing 43 is provided on the other end surface of the third stage sun gear 60 according to this embodiment.
Rolling groove 60C as a recess at the position of the raceway on which
Is formed annularly so as to form a concentric circle with the sun gear 60,
One side surface is a flat raceway surface 60D on which each ball 44A of the fourth ball bearing 44 rolls. Each ball 43A of the third ball bearing 43 rolls between the raceway surface 54D of the second stage sun gear 54 and the rolling groove 60C of the third stage sun gear 60, and the rolling groove 60C. Is positioned in the radial direction to prevent the falling off.

The carrier 6 of the third stage according to this embodiment is also used.
4, the one end surface 64B abuts on the stopper portion 1B of the support member 1 to perform positioning on one side in the axial direction, and the balls 44A of the fourth ball bearing 44 roll on the other side surface. A rolling groove 64C as a recess is formed at the surface position so as to form a concentric circle on the carrier 64. The balls 44A of the fourth ball bearing 44 are the sun gear 6 of the third stage.
0 raceway surface 60D and rolling groove 64 of the third stage carrier 64
It rolls between C and C, and is positioned in the radial direction by the rolling groove 64C to prevent falling off.

Reference numerals 65 and 66 denote positioning rings provided on the other side of the small-diameter tooth portions 54A and 60A of the sun gears 54 and 60. The positioning rings 65 and 66 are the carrier 5
By slidingly contacting the other ends of the tooth portions 52A and 58A of 2, 58, respectively, the carriers 52 and 58 are axially positioned and the planetary gears 49 and 55 are also axially positioned.

The planetary gear speed reducer according to the present embodiment has the above-mentioned structure, and its basic operation is not significantly different from that of the prior art.

Therefore, the sun gear 4 of each stage according to the present embodiment
8, 54 and 60 are axially positioned by the bottom cover 45, the sun gears 48, 54 and 60 of each stage and the carrier 6 of the final stage.
The first to fourth ball bearings 41 to 44 provided between the four ball bearings 41 to 44 are provided, and one of the raceways on which the balls 41A to 44A of the ball bearings 41 to 44 roll is formed as a recess. Rolling grooves 48B, 54C, 60C, 64C, and the other surface is a flat raceway surface 45B, 48B, 54D,
Since it is set to 60D, the reduction gear mechanisms 47, 53, 59 of the respective stages of the planetary gear reduction device can be positioned in the axial direction and the radial direction without impairing the equal distribution mechanism, and the oil contained in the housing 3 The sun gears 48, 54, 60 at the respective stages can be smoothly rotated relative to each other by the ball bearings 41 to 44 through the liquid.

Thus, the sun gears 48, 54, 6 of each stage
0 is axially positioned via the ball bearings 41 to 44 respectively arranged between the bottom cover 45 and the final stage carrier 64, and the first and second stage carriers 5 which transmit only the revolution.
2, 58 are axially positioned and meshed with the sun gears 54, 60 of the next stage via positioning rings 65, 66, so that the planetary gears 49, 55, 61 of each stage are also axially positioned. be able to.

Therefore, the sun gears 48, 54, 60 of each stage
Is axially positioned via the ball bearings 41 to 44 and is relatively rotated via the balls 41A to 44A, the sliding friction resistance generated in the sliding portion as in the conventional technique is It is possible to significantly reduce the sliding resistance by changing the rolling frictional resistance by the ball bearings 41 to 44.

Further, it is possible to reliably prevent seizure and abrasion of the sliding portion which has conventionally occurred, eliminate the backlash at the meshing portion of each component, and greatly improve the durability.

In the above embodiment, each ball bearing 41 to 4 is used.
4 is positioned in the radial direction on the one raceway surface on which the balls 41A to 44A roll, and rolling grooves 48A, 54C,
Although it is described as being performed by 60C and 64C, the present invention is not limited to this, and an annular rolling groove may be formed on the other raceway surface, and the rolling grooves may be formed on both raceway surfaces respectively. May be.

Next, FIG. 3 shows a second embodiment of the present invention. The feature of this embodiment is that the positioning of each ball bearing in the radial direction is determined by the bottom cover, the second stage sun gear, and the final stage. This is done by the annular projections formed inside the sun gear and the carrier at the final stage. In this embodiment, the same components as those in the first embodiment described above are designated by the same reference numerals, and the description thereof will be omitted.

In the figure, 71 indicates a bottom lid according to this embodiment,
The bottom lid 71 is fixed to the ring gear 5 by bolts 11 in the same manner as the bottom lid 45 described in the first embodiment. Although the annular convex portion 71A is formed by the
An annular projection 71B with which the inner cage 41B of the first ball bearing 41 is engaged is formed on the tip side of the annular projection 71B.
The radially outer portion of A is a flat raceway surface 71C on which the balls 41A roll.

Reference numeral 72 denotes a rotary shaft according to this embodiment for deriving the output rotation of the hydraulic motor 2. One end side of the rotary shaft 72 is connected to the hydraulic motor 2 and the other end side thereof extends toward the bottom lid 71. The sun gear 73 of the first stage is formed. Here, the other end surface of the sun gear 73 has the first ball bearing 4
One ball 41A has a flat raceway surface 73A on which the balls roll, and one end surface has a flat raceway surface 73B on which the balls 42A of the second ball bearing 42 roll.

Then, the inner cage 4 of the first ball bearing 41
1B is engaged with the annular protrusion 71B of the bottom lid 71 to perform radial positioning, and the raceway surface 71 of the bottom lid 71 is positioned.
C, each ball 41A is rolled between the track surface 73A of the first stage sun gear 73.

Reference numeral 74 denotes a second stage sun gear, and the sun gear 74 constitutes a second stage reduction gear mechanism 53 together with the planetary gear 55, the carrier 58 and the like like the sun gear 54 according to the first embodiment. An annular protrusion 74A with which the inner cage 42B of the second ball bearing 42 is engaged with the other end of the sun gear 74.
Are formed. In the sun gear 74, the radially outer portion of the annular protrusion 74A serves as a flat raceway surface 74B on which the balls 42A of the second ball bearing 42 roll, and one end surface of each of the third ball bearings 43. It is a flat raceway surface 74C on which the ball 43A rolls.

The second ball bearing 42 is the inner cage 4
2B is engaged with the annular projection 74A of the second stage sun gear 74 to perform radial positioning, and the raceway surface 73B of the first stage sun gear 73 and the second stage sun gear 74
Each ball 42A is rolled between itself and the track surface 74B.

Reference numeral 75 denotes a third-stage sun gear. The sun gear 75 has a planetary gear 61, a carrier 76, which will be described later, and the like, and a third-stage reduction gear mechanism 59 as in the sun gear 60 according to the first embodiment. The sun gear 75 has a third end on the other end side.
An annular protrusion 75A with which the inner cage 43B of the ball bearing 43 is engaged is formed. In the sun gear 75, a radially outer portion of the annular projection 75A serves as a flat raceway surface 75B on which the balls 43A of the third ball bearing 43 roll, and one end surface of each of the fourth ball bearings 44. It is a flat raceway surface 75C on which the ball 44A rolls.

The third ball bearing 43 is the inner cage 4
Positioning is performed in the radial direction by engaging 3B with the annular projection 75A of the third stage sun gear 75, and the raceway surface 74C of the second stage sun gear 74 and the third stage sun gear 75
Each ball 43A rolls between itself and the track surface 75B.

Reference numeral 76 denotes a third-stage carrier which is the final stage. The carrier 76 holds the planetary gear 61 through the pin 63 and the bearing 62 on the other side, and the inner periphery of the one end side is the inner side of the hub 13. A tooth portion 76A that meshes with the tooth portion 13A is formed. The carrier 76 has one end face 76.
B abuts on the stopper portion 1B of the support member 1 and is positioned in one axial direction. Further, the carrier 76 is formed at the other end thereof with an annular protrusion 76C with which the inner cage 44B of the fourth ball bearing 44 is engaged.
The radially outer portion of each of the balls 44A of the fourth ball bearing 44 is
Is a flat raceway surface 76D on which is rolled.

The fourth ball bearing 44 is the inner cage 4
4B is engaged with the annular projection 76C of the third-stage carrier 76 to perform radial positioning, and the raceway surface 75C of the third-stage sun gear 75, the third-stage carrier 76
Each ball 43A is rolled between itself and the track surface 76D.

In this embodiment having such a structure, it is possible to obtain substantially the same operational effects as those of the first embodiment described above, but particularly in this embodiment, the ball bearings 41 to 44 can be formed in a small size. At the same time, it can be effectively used when it is difficult to prevent the balls 41A to 44A from falling off with the rolling groove as the annular recess according to the first embodiment.

In the second embodiment, the annular projections 7 for positioning the ball bearings 41 to 44 in the radial direction.
1B, 74A, 75A, 76C on the bottom cover 71, the second sun gear 74, the final stage sun gear 75, the final stage carrier 7
However, the present invention is not limited to this, and the present invention is not limited to this, and the surface opposite to the member on which the annular protrusions 71B, 74A, 75A, and 76C are formed, that is, the first stage sun gear 73 It may be formed on the other end face and one end face, one end face of the second stage sun gear 74, and one end face of the third stage sun gear 75.

Next, FIG. 4 shows a third embodiment of the present invention. The feature of this embodiment is that the positioning of each ball bearing in the radial direction is performed by a bottom cover, a first stage carrier, and a second stage. This is done by the annular step portions that are annular protrusions formed on the carrier and the final stage carrier, respectively. In this embodiment, the same components as those in the first embodiment described above are designated by the same reference numerals, and the description thereof will be omitted.

In the figure, reference numerals 81, 82, 83 and 84 denote first, second, third and fourth ball bearings as rolling bearings according to this embodiment, and each of the ball bearings 81 to 84 is plural. 81A as a rolling element formed by a steel ball, etc.
˜84A and circular holding holes 81B˜84B for rotatably holding the balls 81A˜84A.
The holding plates 81C to 84C are formed of annular flat plates corresponding to the number of 84A. The first ball bearing 81 is provided between a bottom lid 85 and a first-step sun gear 73, which will be described later, and the second ball bearing 82 is provided with a first-step sun gear 73 and a second-step sun gear 87. In the meantime, the third ball bearing 83 becomes the final stage with the second stage sun gear 87.
Between the sun gear 89 at the stage and the fourth ball bearing 8
4 is the sun gear 89 of the third stage and the carrier 90 of the third stage
And are respectively disposed between and.

Reference numeral 85 denotes a bottom lid according to the present embodiment which constitutes a part of the housing 3. The bottom lid 85 is similar to the bottom lid 45 described in the first embodiment, and the ring gear 5 is fixed by the bolts 11. The bottom of the bottom lid 85 is fixed to the rotary shaft 72.
An annular convex portion 8 protruding toward one side so as to form a concentric circle with
Although 5A is formed, an annular stepped portion 85B with which the holding plate 81C of the first ball bearing 81 is engaged is formed on the tip surface side of the annular convex portion 85A. Also, the annular convex portion 85A
Is the first ball bearing 81 at the radially inner portion of the annular step portion 85B.
Is a flat raceway surface 85C on which each ball 81A is rolled.

Reference numeral 86 denotes a first stage carrier. The carrier 86 transmits the revolution of the planetary gear 49 of the first stage reduction gear mechanism 47 to the next stage sun gear 87, and the inner circumference of the carrier 86. The side is engaged with the holding plate 82C of the ball bearing 82,
An annular step portion 86A for positioning the ball bearing 82 in the radial direction is formed so as to be concentric with the sun gears 73, 87 and the like.

The first ball bearing 81 is a holding plate 81C.
Are positioned in the radial direction by engaging with the annular step portion 85B of the bottom lid 85, and each ball 81A is positioned between the raceway surface 85C of the bottom lid 85 and the raceway surface 73A of the first stage sun gear 73.
To roll.

Numeral 87 indicates a second stage sun gear, and the sun gear 87 constitutes a second stage reduction gear mechanism 53 together with the planetary gear 55 and the carrier 88 similarly to the sun gear 54 of the first embodiment, The other end side of the sun gear 87 is a flat raceway surface 87A on which the balls 82A of the second ball bearing 82 roll, and the one end side is flat on which the balls 83A of the third ball bearing 83 roll. It is a raceway surface 87B.

The second ball bearing 82 is a holding plate 82C.
Is engaged with the annular stepped portion 86A of the first-stage carrier 86 to be positioned in the radial direction, and the first-stage sun gear 7
3 orbital surface 73B, the orbital surface 87 of the second stage sun gear 87
Roll each ball 81A between itself and A.

Reference numeral 88 denotes a second stage carrier, which transmits the revolution of the planetary gear 55 of the second stage reduction gear mechanism 53 to the next stage sun gear 89, and the inner circumference of the carrier 88. On the side, an annular step portion 8 that engages with the holding plate 83C of the third ball bearing 83 and positions the ball bearing 83 in the radial direction.
8A is formed so as to form a concentric circle with the sun gears 73, 87 and the like.

Reference numeral 89 denotes a third stage sun gear, which is the second stage reduction gear mechanism 59 together with the planet gear 55, the carrier 90, etc., similarly to the sun gear 60 of the first embodiment.
And the other end of the sun gear 89 has a third ball bearing 83.
Each ball 83A is a flat raceway surface 89A on which the balls are rolled, and one end side is a flat raceway surface 89B on which each ball 84A of the fourth ball bearing 84 is rolled.

The third ball bearing 83 is a holding plate 83C.
Is positioned in the radial direction by engaging the second step carrier 88A with the annular step portion 88A, and the second step sun gear 8
7, orbital surface 89 of third sun gear 89
Each ball 83A of the third ball bearing 83 rolls between itself and A.

Reference numeral 90 designates a third-stage carrier which is the final stage. The carrier 90 holds the planetary gear 61 on the other side through a pin 63 and a bearing 62, and at the inner circumference of one end side, the inner side of the hub 13 is provided. A tooth portion 90A that meshes with the tooth portion 13A is formed. The carrier 90 has one end face 90B.
Comes into contact with the stopper portion 1B of the support member 1 and is positioned on one side in the axial direction. Further, the carrier 90 has an annular step portion 90 with which the holding plate 84C of the ball bearing 84 engages on the other end side.
C is formed, and the radially outer portion of the annular stepped portion 90C becomes a flat raceway surface 90D on which the balls 84A of the fourth ball bearing 84 roll.

The fourth ball bearing 84 is a holding plate 84C.
Is positioned in the radial direction by being engaged with the annular step portion 90C of the third stage carrier 90, and the third stage sun gear 8
9 raceway surface 89B, 3rd stage carrier 90 raceway surface 90
Each ball 84A of the ball bearing 84 rolls between itself and D.

In this embodiment having the above-described structure, it is possible to obtain substantially the same operational effects as those of the first and second embodiments described above. However, particularly in this embodiment, the ball bearings 81 to 81 are used. An annular plate 81C including a retainer 84 made of an annular flat plate.
Since it is formed of 84C, the assembling of the ball bearings 81 to 84 can be improved.

In each of the above-mentioned embodiments, the case where the reduction gear mechanism is composed of a three-stage speed reducer has been described as an example, but the present invention is not limited to this, and two-stage or four-stage.
You may use it for what has the reduction gear mechanism of a step or more. Further, the drum 4 and the ring gear 5 may be integrally formed, or the ring gear 5 and the bottom cover 45 (71, 85) may be integrally formed.

Further, in each of the above-described embodiments, the balls 41A to 44A (81A to 84A) are used as rolling elements for the rolling bearings.
However, the present invention is not limited to this, and drum-shaped spherical rollers or tapered rollers may be used as the rolling elements.

[0069]

As described above in detail, in the planetary gear speed reducer according to the present invention, the axial positioning of each sun gear constituting each speed reduction gear mechanism is determined by the first stage sun gear and the bottom cover of the housing. Between the sun gears of each stage, and between the sun gears of the final stage and the carrier of the final stage by means of rolling bearings, and each bearing is radially positioned by the radial positioning means. Therefore, it is possible to remarkably reduce the sliding resistance of each sun gear by changing it to rolling resistance, and it is possible to effectively prevent seizure and wear of the sliding portion. Then, it is possible to improve the output efficiency and the life of the reduction gear without damaging the even distribution mechanism of each reduction gear mechanism.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a planetary gear speed reducer according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing an enlarged main part in FIG.

FIG. 3 is an enlarged cross-sectional view of essential parts of a planetary gear speed reducer according to a second embodiment of the present invention.

FIG. 4 is an enlarged cross-sectional view of essential parts of a planetary gear speed reducer according to a third embodiment of the present invention.

FIG. 5 is a vertical cross-sectional view of a planetary gear speed reducer according to the related art.

FIG. 6 is an enlarged cross-sectional view showing a main part in FIG.

[Explanation of symbols]

1 Support Member 2 Hydraulic Motor (Rotation Source) 3 Housing 4 Drum 5 Ring Gear 5A Internal Gear 13 Hub 13A Inner Teeth 13B Outer Teeth 41, 42, 43, 44 Ball Bearings (Rolling Bearings) 41A, 42A, 43A , 44A Ball (rolling element) 41B, 42B, 43B, 44B Inner cage 41C, 42C, 43C, 44C Outer cage 45, 71, 85 Bottom lid 45B, 48B, 54D, 60D, 71C, 73A, 7
3B, 74B, 74C, 75B, 75C, 76D, 85
C, 87A, 87B, 89A, 89B, 90D Raceway surface 46, 72 Rotating shaft 47, 53, 59 Reduction gear mechanism 48, 54, 60, 73, 74, 87, 89 Sun gear 48A, 54C, 60C, 64C Rolling Grooves (recesses) 49, 55, 61 Planetary gears 50, 56, 62 Bearings 51, 57, 63 Pins 52, 58, 64, 76, 86, 88, 90 Carriers 71B, 74A, 75A, 76C Annular protrusions 81, 82 , 83, 84 Ball bearings (rolling bearings) 81A, 82A, 83A, 84A Balls (rolling elements) 81B, 82B, 83B, 84B Holding holes 81C, 82C, 83C, 84C Holding plate 85B, 86A, 88A, 90C Annular step (Annular protrusion)

Claims (3)

[Claims] 1. A support member provided with a rotation source, a cylindrical housing with a lid rotatably supported by the support member, and an internal gear provided on the inner peripheral side, and a rotation output of the rotation source. In order to take out, one end side is connected to the rotation source, the other end side extends to the bottom lid side of the housing, and the rotation of the rotation shaft is decelerated and transmitted to the housing. A planetary gear that meshes with a gear and the internal gear, and a reduction gear mechanism of a plurality of stages including a carrier that supports the planetary gear, and the carrier of the final stage is positioned in the axial direction and the rotation direction by the support member. In the planetary gear speed reducer, axial positioning is performed between the sun gear of the first stage and the bottom lid of the housing, between the sun gears of each stage, and between the sun gear of the last stage and the carrier of the last stage. Multiple rolling to A planetary gear reduction device comprising a bearing and radial positioning means for positioning each rolling bearing in the radial direction. 2. The planetary gear speed reducer according to claim 1, wherein the radial positioning means is a concave portion formed on a raceway surface of each of the rolling bearings and rotatably holding each of the rolling bearings. 3. The radial positioning means is an annular protrusion that is formed at a plurality of required positions of the bottom lid of the housing, the sun gears, and the carriers, and positions the rolling bearings in the radial direction. The planetary gear speed reducer according to claim 1.